Thermally controlled release mechanism



Aug .26, 1941. F. McK NE EAL 2,253,861

THERMALLY CONTROLLED RELEASE MECHANISM Filed Sept. 11, 1940 3 Sheets-Sheet 1 INVENTORS DONALD W. KENNEDY BY FRA/V YMCKUNE' I Aug. 26; 1941. F, McKUNE ETYAL 2,253,861

THERMALLY CONTROLLED RELEASE MECHANISM Filed Sept. 11, 1940 s Sheets-Sheet 2 "my Q 38 4 m 66 40 K 65 55 64 E6 50 FIG IO INVENTORS DONALD W KENNEDY RNEYS Aug. 26, 1941. F. MQQKUNE HAL 2,253,861

THERMALLY CONTROLLED RELEASE MECHANISM Filed Sent. 11, 1940 3 Sheets-Sheet 3 INVENTORS I 001mm W. KENNEDY Patented Aug. 26, 1941 UNITED THERMALLY CONTROLLED RELEASE MECHANISM Frank McKune and Donald W. Kennedy, Seattle, Wash.

Application September 11, 1940, Serial No. 356,308

14 Claims. (01. 189-49) Our present invention relates to a thermally controlled release mechanism primarily designed for use in connection with fire doors or fire windowsor the like. It will, of course, be understood that there is no limitation to our invention; that the following description may be applied to fire doors or fire windows because it is conceived that many other uses may be made for the mechanism.

The release mechanisms previously used for controlling fire doors and the like have usually been of the type employing a fusible strip-such a fusible strip is designed to melt or destroy itself upon the application of sufiicient heat. In such cases where the fusible strip is employed to hold a fire door in anopen position, the occurrence of a fire in the vicinity will cause the strip to fuse, presumably, and release the door. In such an arrangement, of course, the mechanism may be tested by fusing the strip artificially, or intentionally, but conclusive proof that any given fire will fuse the strip is not established. It is a matter of common knowledge that many devices of this nature have failed at the crucial moment and much damage has resulted. Other devices than the fusible strip type have also been employed but the same objections have been advanced against them.

An important object of our invention has been to provide a release mechanism under control of Another object of our invention has been the I provision of a, release mechanism capable of being adjusted delicately for operation and which may be tested and give adequate proof that it will operate should fire occur.

A further object of our invention is the provision of a release mechanism which may be attached to a door and so adjusted as to vary the degree of opening that it may be desired to maintain by the door.

Still another object of the invention is the provision in a release mechanism of means for overcoming inertia. to insure that parts of the mechanism that may not have been operated for a long period of time will be positively operated.

A still further object of the invention is the provision in the release mechanism of gravity actuated latch dislodging means, which will assure the proper functioning of the mechanism when its function is desired.

Other objects of the invention relate to the provision of a release mechanism under thermal operation.

control means whichmay be constructed with the minimum, of parts and thus easily manufactured and assembled and still, at the same time, produce a device having a maximum of emciency in Further objects and advantages of the invention will be apparent during the course of the following description, wherein is disclosed a preferred embodiment of our invention.

For the purposes of making more readily understood the principles of the invention, the invention will'be described as though applied to a door, preferably a fire door, but this description is purely exemplified and we do not Wish to be limited to the application of our invention to this single use.

Referring now to the drawings Figure 1 is a perspective view of our release mechanism with the parts adjusted and set in their latched positions, but showing the mechanism disassembled from a door, or the like, "Figure 2 is an elevational View of our latch mechanism attached to a door and the surrounding wall structure and illustrating the door in the closed position,

Figure 3 is a plan view of the latch mechanism on a somewhat larger scale than disclosed in Figure 2, and illustrating the general arrangement in which the mechanism is attachedto the door and the door header,

Figures 4, 5, 6, '7 and 8 are partial, sectional views through the mechanism illustrating the various positions assumed by the mechanism from the latched position to the unlatched position when the thermal release element has been actuated mechanically or by the application of heat,

Figures 9 and 10 are similar views in elevation illustrating the steps of resetting the mechanism for future operation,

Figure 11 is a plan view of fragments of brace arms illustrating the general arrangement of parts, I Figure 12 is a similar plan View taken as though on line l2|2 of Figure 6, but with the release arm having been actuated and the brace arms being in a closing position,

Figure 13 is a plan view with portions in section as though taken on line l3l3 of Figure 4,

Figure 14 is an inverted perspective View of the 7 thermal latch mechanism,

Figur 15 is a perspective view of the hammer arm employed in the mechanism,

Figure 16 is a perspective view of the bell crank latch and'anvil employed in the mechanism,

Figure 17 is a view in perspective of the reset arm which we provide in certain instances in our mechanism, and

Figure 18 is a perspective view of an extensible type of brace arm with the portions separated for convenience of illustration.

In Figures 2 and 3, the numeral 20 refers to a door having a hinged member 22 in paired relation to its face. A matching hinge member 24 is secured to the face of a wall 26 which may be the wall of a building or the door jamb, as the case may be.

A suitable latch bar 28 cooperates with a keeper 30 to secure the door in closed position. A clip 3| may be fastened to the top edge of the door and a cable 32 is led over a sheave 33 and has the weight 34. The weight 34 constantly urges the door 2|] into the closed position of Figure 2 from the open position of Figure 3.-

The perspective view of Figure 1 illustrates the general arrangement of the mechanism which we employ to brace the door in the open position shown in Figure 3.

The brace mechanism consists essentially of a pair of brace arms which are secured at each end pivotally between the door and the door jamb. The mechanism operates to normally hold the door in open position except when the latch is released due to the application of a dangerously high heat, which will cause the latch to be released and the door be permitted to be closed by the action of the weight or other closure means applied to the door.

A brace arm 36 having a pivot hole 31 is provided with the head 38. The head 38 is pivotally secured to the head 48 by means of the pivot bolt 4! and the head 43 has a similar brace arm 42.

In Figures 1 and 3, the brace arm 42 is shown as an extensible arm and has the extension 43 and a pivot hole 44. In Figure 18 the extension 43 also has the slot 45 and a pair of bolts 46 are passed through the arm 42 and the slot 45 and nut 4'! holds the arm in an adjusted extensible position.

As may be seen in Figure 18, the pivot heads 38 and 40, are provided with an inner annular groove 48 and 49 respectively. A spacer washer 56 may be positioned between the heads 38 and 4E! and a spring 52 is also anchored in the grooves 48 and 49 and encircles the washer 50. The pivot bolt is provided with a nut 53 to tightly close the pieces together for pivotal action.

Spring 52 has a hook formed on each end and that hook may be inserted into a hole 54 in the bottom of the groove 43 and of course a similar hole would be provided in the bottom of the groove 48. The normal urgence of the spring is in the direction to close the door. When the spring is placed in the two grooves 48 and 49 a sufficient amount of twist or tension is applied to cause it to slowly close the door when the latch is dislodged. The primary function of the spring is to overcome the normal inertia imparted by the weight of the door and to start it to close despite the nonoperability of the weight and cord or other closure. Supported from the head 49 is a pair of pivot arms 55 and 56 which are normally spaced apart and have pivot holes as at their outer 'head 40.

or looking lug 62. Approximately at the bend of the two arms 60 and BI we provide a pivot hole 63 and a pivot pin 64 passes through the holes 63 and the holes 51, 57. Aligned with the space between the arms 55 and 56 is a notch 65 in the The head 38 is also provided with a notch 66 and when the two notches 65 and 66 are in alignment the lug or latching member 62 may be inserted therein and retain the two brace arms attached to each of the heads in the proper aligned position. Sufficient urgence on the spring 52 will tend to keep the head and the latch member in this latched position.

As may be seen in Figure 15, a hammer lever comprising a yoke 68 has the hammer 69 and the latching horn 10. The two arms of the yoke H,

H, each is provided with pivot holes 12, 12 and they also are pivoted on the pin 64, but straddle the pivot arms 55 and 58 and the bell-crank latch member 58 which is pivoted therebetween.

On the upper face of the head 38 we mount a non-heat-conducting anchor block '14 which has secured thereto the thermal arm 16 by means of the screw 11. A beveled hook 18 on the outer end of the arm 16 engages the latching horn 10 of the yoke 68.

Also suspended from the pivot pin 64 is the reset arm which is shown in Figure 17 to have an added weight 8| at its lower end and a pivot head 82 on the upper end provided with a hole 83 adapted to be fitted over the pin 64. An outstanding lug or pin 84 is also provided adjacent the pivot head, as well as a Z-shaped head 86 which has the outstanding horn 81 on its outer eccentric end.

In the showings of Figures 2 and 3 the arm 35 is pivotally attached to a bracket 93 which in turn is secured by means of a bolt or rivet 9| to the header of the door frame or door opening, and the arms 42, 43 are similarly pivoted to a bracket 92 which is secured on the upper face of the door. The arm 36 is pivoted on the bracket by means of the pivot pin 95 and the arm 42, 43 is pivoted on the bracket 82 by means of the pivot pin 96.

Mode of operation When our device is assembled and set as shown in the Figures 1 and 3 it will serve to brace the door in an open position. Of course it will be apparent that by minor changes the door can be operated in an alternate direction, whereby the mechanism would hold the door in a closed position, and upon release would permit the opening of the door if that be desired.

According to the showings of Figures 1 and 3, however, the mechanism would hold the door in the open position, and the latch member 62 would be firmly engaged in the notches in the heads 38 and 40. If the door should be accidentally bumped, the spring 52 will serve to maintain suificient tension on the two arms of the bracing mechanism to prevent the accidental dislodgement of the latch 52 from the notches.

The thermally actuated latch arm 16 and its hook 18 secure the yoke in the raised position of Figure 1 and also of Figure 4 by reason of the hook 18 engaging the horn T0. The hammer or weighted end 59 of the yoke is in alignment with the anvil 59 on the arm 63. Upon the application of sufficient heat to cause the expansion of the latch i6 and the consequent disengagement of the hook 78 from the horn 10, the anvil will be struck a forceful blow by the hammer 69 causing the horn 62 to dislodge from the adjacent notches in the head 38 and in thehead 40'.

The start of the falling stroke of the yoke and its hammer is illustrated in 'Figure'5, wherein the hook 18 is shown as free from the horn Hi. In Figure 6, the hammer is striking the anvil, but the latch member 62 has not been disengaged from the notches 65 and 65 of the heads 38 and 40 respectively. As the hammer strikes the anvil and the horn or latch 62 slips out of the notches it assumes the position shown in Figure 7, wherein both parts are falling freely to the position where they will come to rest as in Figure 8.

The moment that the latch disengages from the notches in the head members, the weight 34, or other closure means which may be provided for the door, will cause the door to swing shut and to serve whatever purpose it was intended. In cases where the door 20 is a fire door, its closure will prevent the movement of undesirable drafts and the like.

To reset the latching mechanism to the position shown in Figure 4, the door must be opened, substantially as may be seen in Figure 3, and the reset arm 80 will be grasped and caused to pivot in a counter-clockwise motion, as is shown in Figures!) and 10. The pin 84 engages the leg H of the yoke 68 and the horn 8'! of the Z-shaped member 36 engages the arm 55 of the bell-crank latch member.

Due to the spaced-apart position of the members 84 and 87, a certain timing arrangement can be obtained to cause the latch arm and the yoke to travel in a predetermined relationship. 1

The latching horn of the yoke will slip past the hook 13 of the latch member 15, as is shown in Figure. 10, so that the latch 62 will be firmly seated in the aligned notches of the two heads. When the reset lever 85! is released the yoke will assume the position of Figure 4 with the hook 18 and the horn ill in proper engagement.

The member 15 is formed of a material which will be extremely sensitive to unnaturally high temperatures, and should be in fact or a thermal metal which rapidly expands. The operation, of course, when fire occurs, is that the head causes the arm 76 to expand and to thus dislodge the hook "581 from the latching horn Ii and permitting the gravity actuated part to operate as before described.

The arms 42 and 43 may be provided as one solid arm or extensible as is shown in the drawings. The purpose of the extensible feature of the arm is to permit the ready adaptation of i the device to practically all types of doors that may be encountered, as well as to provide different degrees of leverage between the parts if that is also desirable.

It is an important function of our device that it can be tested by the artificial application of a heat sufficiently high to operate the latch member 16, as for example, a match may be used or an open flame or also an electrical heater element. merely applies the heat to the member 16 and that can be done under controlled temperatures so that a delicate adjustment will be obtained. Then, when the hammer starts to fall and strikes the anvil, it can be definitely determined that the mechanism is operating at any desired temperature, and the presumption will always be that it will also operate at that same temperature at any later date when called upon to do so.

Another function of the invention has been in The person testing the mechanism providing-a hammer and anvil arrangement so that the, latch 62 will definitely andcertainly be dislodged from the notches rather than depending entirely upon the action of gravity on the arm or lever 69.

The foregoing descriptionand the accompanying drawings are believed to clearly disclose a preferred embodiment-of our invention, but it will be understood that this disclosure is merely illustrative and that such changes in the invention may be made as. are fairly within the scope and spirit of the following claims.

We claim:

1. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each arm including a pivot head having a notch capable of being aligned with a notch in the other head when they are placed in an adjusted position, pivot arms on the lower of said pivot heads, a bell-crank latch pivoted on said pivot, arms and'having a latch leg cooperable with the said notches when they are aligned to retain the brace arm in adjusted position, said bell-crank latch arm also having an anvil leg, a gravity-actuated hammer lever mounted on said pivot arms for swinging movement into engagement with said anvil lever, a reset lever pivoted on said pivot arms and cooperable with said bellcrank latch and said hammer lever, and. thermally operated means for retaining said hammer leg in a raised position above said anvil leg whereby, the exposure of the thermally operated means to abnormal heat will effect the release of the hammer lever to the urgence of gravity causing the hammer to strike the anvil leg to effect the disengagement of the latch lever from the aligned notches.

2. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each arm including a pivot head having a notch capable of being aligned with a notch in the other head when they are placed in an adjusted position, pivot/ arms on the. lower of said pivot heads, a bell-crank latch pivoted on said pivot arms and having a latch leg cooperable with the said notches when they are aligned to'retain the brace arm in adjusted position, said bell-crank latch arm also having an anvil leg, a gravity-actuated hammer lever mounted on said pivot arms for swinging movement into engagement with said anvil lever, and thermally operated means for retaining said hammer leg in a raised position above said anvil leg whereby the exposure of the thermally operated means to abnormal heat will effect the release of the hammer lever to the urgence of gravity causing the hammer to strike the anvil leg to effect the disengagement of the latch lever from the aligned notches.

3. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each arm including a pivot head having a notch capable of being aligned with a notch in the other head when they are placed in an adjusted position, a pivoted bell-crank latch having a latch leg cooperable with the said notches when they are aligned to retain the brace arm in adjusted position, said bell-crank latch arm also having an anvil leg, a gravity-actuated hammer lever mounted for swinging movement into engagement with said anvil lever, a reset lever pivoted adjacent said bell-crank latch and cooperable with said latch and said hammer lever, and thermally operated means for retaining said hammer leg in a raised position above said anvil leg whereby the exposure of the thermally operated means to abnormal heat will effect the release of the hammer lever to the urgence of gravity causing the hammer to strike the anvil leg to effect the disengagement of the latch lever from the aligned notches.

4. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each arm including a pivot head having a notch capable of being aligned with a notch in the other head when they are placed in an adjusted position, a coil tension spring anchored at each end to a pivot head and positioned therebetween, a pivoted bell-crank latch having a latch leg cooperable with the said notches when they are aligned to retain the brace arm in adjusted position, said bell-crank latch arm also having an anvil leg, a gravity-actuated hammer lever mounted for swinging movement into engagement with said anvil lever, and thermally operated means for retaining said hammer leg in a raised position above said anvil leg whereby the exposure of the thermally operated means to abnormal heat will eifect the release of the hammer lever to the urgence of gravity causing the hammer to strike the anvil leg to effect the disengagement of the latch lever from the aligned notches.

5. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each arm including a pivot head having a notch capable of being aligned with a notch in the other head when they are placed in an adjusted position, a pivoted bell-crank latch having a latch leg cooperable with the said notches when they are aligned to retain the brace arms in adjusted position, said bell-crank latch arm also having an anvil leg, a gravity actuated hammer lever mounted for swinging movement into engagement with said anvil leg and having a latching horn, and thermally operated means including a hook cooperable with said latching horn for retaining said hammer lever in a raised position above said anvil leg whereby the exposure of the thermally operated means to abnormal heat will effect the dislodgment of the hook from the latching horn on the hammer lever to release the hammer lever to the urgence of gravity causing the hammer to strike the anvil leg to effect the disengagement of the latch lever from the aligned notches.

6. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each arm including a pivot head having a notch capable of being aligned with a notch in the other head when they are placed in an adjusted position, a pivoted bell-crank latch having a latch leg cooperable with the said notches when they are aligned to retain the brace arms in adjusted position, said bell-crank latch arm also having an anvil leg, a gravity-actuated hammer lever mounted for swinging movement into engagement with said anvil lever, and thermally operated means for retaining said hammer leg in a raised position above said anvil leg whereby the exposure of the thermally operated means to abnormal heat will effect the release of the hammer lever to the urgence of gravity causing the hammer to strike the anvil leg to effect the disengagement of the latch lever from the aligned notches.

'7. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each arm including a pivot head having latch means capable of being aligned with the latch means in the other head when they are placed in an adjusted position, a pivoted bellcrank latch having a latch leg cooperable with the said latch means when they are aligned to retain the brace arms in adjusted position, said bell-crank latch arm also having an anvil leg, a gravity-actuated hammer lever mounted for swinging movement into engagement with said anvil lever, and thermally operated means for retaining said hammer leg in a raised position above said anvil leg whereby the exposure of the thermally operated means to abnormal heat will efiect the release of the hammer lever to the urgence of gravity causing the hammer to strike the anvil leg to effect the disengagement of the latch lever from the aligned notches.

8. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each arm including a pivot head having a notch capable of being aligned with a notch in the other head when they are placed in an adjusted position, a pivoted bell-crank latch having a latch leg cooperable with the said notches when they are aligned to retain the brace arms in adjusted position, said bell-crank latch arm also having an anvil leg, a gravity-actuated lever mounted for swinging movement and having a hammer for engagement with said anvil lever, and thermally operated means for retaining said hammer leg in a raised position above said anvil leg whereby the exposure of the thermally operated means to abnormal heat will effect the release of the hammer lever to the urgence of gravity causing the hammer to strike the anvil leg to effect the disengagement of the latch lever from the aligned notches.

9. A thermally controlled release mechanism comp-rising a pair of tensioned brace arms pivoted together, each brace arm having a notch capable of being aligned with the notch in the other brace arm when they are placed in an adjusted position, a pivoted latch arm having latch means cooperable with the said notches when they are aligned to retain the brace arms in adjusted position, said latch arm also including an anvil portion, a gravity-actuated hammer lever mounted for swinging movement into engagement with said latch arm anvil portion, a reset lever swingingly mounted adjacent and cooperable with said latch arm, and a hammer lever and thermally operated means for retaining said hammer lever in raised position above said latch arm whereby the exposure of the thermally operated means to abnormal heat will efiect the release of the hammer lever to the urgence of gravity permitting said hammer lever to strike said latch arm anvil portion to dislodge the latch means from the aligned notches.

10. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each brace arm having a notch capable of being alined with the notch in the other brace arm when they are placed in an adjusted positlon, a pivoted latch arm having latch means cooperable with the said notches when they are alined to retain the brace arms in adjusted posit on, said latch arm also including an anvil portlon, a gravity-actuated hammer lever mounted for swinging movement into engagement with said latch arm anvil portion, and thermally operated means for retaining said hammer lever in raised position above said latch arm whereby the exposure of the thermally operated mean to abnormal heat will effect the release of the hammer lever to the urgence of gravity permitting said hammer lever to strike said latch arm anvil portion to dislodge the latch means from the alined notches.

11. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each brace arm having an abutment capable of being associated with the abutment in the other brace arm when they are placed in an adjusted position, a pivoted latch arm having latch means cooperable with the said abutments when they are adjusted adjacent each other to retain the brace arms in adjusted position, said latch arm also including an anvil portion, a gravity-actuated hammer lever mounted for swinging movement into engagement with said latch arm anvil portion, and thermally operated means for retaining said hammer lever in raised position above said latch arm whereby the exposure of the thermally operated means to abnormal heat will effect the release of the hammer lever to the urgence of gravity permitting said hammer lever to strike said latch arm anvil portion to dislodge the latch means from the alined notches.

12. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each brace arm having an abutment capable of being associated with the abutment in the other brace arm when they are placed in an adjusted position, a pivoted latch arm having an upright latch means cooperable with the said abutments when they are in adjusted position to retain the brace arms in adjusted position, said latch arm also including a horizontal anvil portion, a gravity-actuated hammer lever mounted for swinging movement into engagement with said latch arm anvil portion, and thermally operated means for retaining said hammer lever in raised position above said latch arm whereby the exposure of the thermally operated means to abnormal heat will effect the release of the hammer lever to the urgence of gravity permitting said hammer lever to strike said latch arm anvil portion to dislodge the latch means from the alined notches.

13. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each brace arm having an abutment capable of being alined with the abutment in the other brace arm when they are placed in an adjusted position, a pivoted latch arm having latch means cooperable with the said abutments when they are in adjusted position to retain the brace arms in adjusted position, said latch arm also including an anvil portion, a gravity-actuated hammer lever mounted for swinging movement into engagement with said latch arm anvil portion and having a latching horn, and thermally operated means including a hook cooperable with the latching horn for retaining said hammer lever in raised position above said latch arm whereby the exposure of the thermally operated means to abnormal heat will dislodge the hook from the latching horn to effect the release of the hammer lever to the urgence of gravity permitting said hammer lever to strike said latch arm anvil portion to dislodge the latch means from the aligned notches.

14. A thermally controlled release mechanism comprising a pair of tensioned brace arms pivoted together, each brace arm having an abutment capable of being aligned with the abutment in the other brace arm when they are placed in an adjusted position, a pivoted latch arm having latch means cooperable with the said abutments when they are in adjusted position to retain the brace arms in adjusted position, said latch arm also including an anvil portion, a gravity-actuated hammer lever mounted for swinging movement into engagement with said latch arm anvil portion and having a latching horn, and thermal arm having a hook cooperable with the latching horn for retaining said hammer lever in raised position above said latch arm whereby the exposure of the thermally operated means to abnormal heat will dislodge the hook from the latching horn to effect the release of the hammer lever to the urgence of gravity permitting said hammer lever to strike said latch arm anvil portion to dislodge the latch means from the aligned notches.

FRANK McKUNE. DONALD W. KENNEDY. 

